The present invention relates to electromagnetic transducers of the type including a member producing a magnetic field and presenting an air gap traversed by the field, a mass of magnetic liquid extending across the air gap, and a moving coil mounted on a moving coil carrier supported for movement through the air gap.
There are known dynamic transducers, specifically loudspeakers as disclosed in German Offenlegungsschrift [Laid-open application] No. 27 40 661.7 in which the area of the magnetic pole element in which the moving coil of the dynamic system moves, an area usually called the "air gap", is filled with fluid on both sides. With the aid of a dosaging, or metering device, the magnetic fluid is introduced separately into the inner and outer air gap regions. The magnetic fluid is retained in the air gap by the permanent magnetic field of the magnetic pole element.